This guy, Ye Tongxin, is freakin' awesome! He's basically dedicated all of his spare time training to slice fruit by throwing playing cards at them. It's pretty damn impressive! He's able to get so much speed and velocity with these cards that they slice through and into various fruits such as cucumbers, apples and even watermelon.
Right after I saw the video I took out a deck of cards and started throwing them at fruit myself... it didn't turn out as awesome. He says that the cards he throws travel up to 360kph, which is pretty insane, and could most likely slice open a person.
Tongxin is currently trying to get the Guinness World Record in fruit slicing. To do that he would have to cut through 19 cucumbers in under a minute with a deadly set of playing cards. Checkout what he's able to acomplish so far!
Source: Oddity Central (http://www.odditycentral.com/news/worlds-deadliest-card-player-slices-fruits-an-vegetables-with-plastic-playing-cards.html)